New radio (NR) networks such as fifth generation (5G) NR networks are designed for deployment in the radio frequency spectrum between 30 GHz and 300 GHz, referred to as the millimeter wave (mmWave) spectrum. Unlike other mobile communication frequency ranges, in the mmWave spectrum, the beam pair between the network (via a distributed unit) and the user equipment may experience a blockage, such as due to a physical obstruction caused by objects near the user, or even the user's own self, which interrupts the communication. The narrow beamforming of NR is also part of such a blockage effect.
There are two technologies introduced in NR to overcome the blockage effect. A first technology is beam management, which is a procedure for user equipment to report back to the network the measured power of received reference signals, referred to as Reference Signal Received Power (RSRP), to select the best beam for transmission. A second technology that overcomes the blockage effect and provides robustness to a connection is beam recovery, which takes place upon beam failure; beam failure is declared when all of the control channel resource sets (CORESET) failed.
Neither beam management nor beam recovery addresses a partial control channel failure, in which one or more control channel beams remain workable, while one or more others are considered to have failed. However, most of the time a recovery signal is not transmitted, and thus it is inefficient to configure resources for such a situation.